Nortel Networks BMD00007 manual Spanning Tree Port Configuration, Prior new port Priority

Alteon OS Command Reference

/cfg/l2/stg <STP Group number>/port <port alias or number>

Spanning Tree Port Configuration

[Spanning Tree Port EXT1		Menu]
prior	- Set port Priority (0-255)
cost	- Set port Path Cost (1-65535 (802.1d) /
link	1-200000000	(MSTP/RSTP) /0 for auto)
	- Set port link type (auto, p2p, or shared; default: auto)
edge	- Enable/disable edge port
on	- Turn port's	Spanning Tree ON
off	- Turn port's	Spanning Tree OFF
cur	- Display current port Spanning Tree parameters

By default for STP/PVST+, Spanning Tree is turned Off for internal ports and management ports, and turned On for external ports. By default for RSTP/MSTP, Spanning Tree is turned Off for internal ports and management ports, and turned On for external ports, with internal ports configured as Edge ports. STG port parameters include:

„Port priority

„Port path cost

The port option of STG is turned on by default.

Table 6-39Spanning Tree Port Menu Options (/cfg/l2/stg/port)

Command Syntax and Usage

prior <new port Priority (0-255)>

Configures the port priority. The port priority helps determine which bridge port becomes the des- ignated port. In a network topology that has multiple bridge ports connected to a single segment, the port with the lowest port priority becomes the designated port for the segment. The default value is 128.

RSTP/MSTP: The range is 0 to 240, in steps of 16 (0, 16, 32...) and the default is 128.

cost <new port Path Cost (1-65535, 0 for default)>

Configures the port path cost. The port path cost is used to help determine the designated port for a segment. Generally speaking, the faster the port, the lower the path cost. The default is 19 for 100Mbps ports, 4 for 1Gb ports and 2 for 10 Gb ports. A value of 0 (zero) indicates that the default cost will be computed for an auto negotiated link speed.

link <auto, p2p, or shared; default: auto>

Defines the type of link connected to the port, as follows:

auto: Configures the port to detect the link type, and automatically match its settings.

p2p: Configures the port for Point-To-Point protocol.

shared: Configures the port to connect to a shared medium (usually a hub).

BMD00007, November 2007 The Configuration Menu „ 235